Ophthalmic lens assembly having an integrated antenna structure

ABSTRACT

Antennas and antenna systems may be designed and configured for incorporation into mechanical devices, including medical devices, such as ophthalmic devices, including contact lenses. These antennas and antenna systems may be utilized to transmit data from the mechanical device to a receiver, to receive data from a transmitter, and/or to inductively charge an electromechanical cell or the like incorporated into the mechanical device.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention is directed to optical lenses, and moreparticularly to optical lenses, such as wearable lenses, includingcontact lenses, implantable lenses, including intraocular lenses (IOLs)and any other type of device comprising an optical component thatincorporates electronic circuits and associated antennas/antennaassemblies for information reception, information transmission and/orcharging/energy harvesting.

2. Discussion of the Related Art

As electronic devices continue to be miniaturized, it is becomingincreasingly more likely to create wearable or embeddablemicroelectronic devices for a variety of uses. Such uses may includemonitoring aspects of body chemistry, administering controlled dosagesof medications or therapeutic agents via various mechanisms, includingautomatically, in response to measurements, or in response to externalcontrol signals, and augmenting the performance of organs or tissues.Examples of such devices include glucose infusion pumps, pacemakers,defibrillators, ventricular assist devices and neurostimulators. A new,particularly useful field of application is in ophthalmic wearablelenses and contact lenses. For example, a wearable lens may incorporatea lens assembly having an electronically adjustable focus to augment orenhance performance of the eye. In another example, either with orwithout adjustable focus, a wearable contact lens may incorporateelectronic sensors to detect concentrations of particular chemicals inthe precorneal (tear) film. The use of embedded electronics in a lensassembly introduces a potential requirement for communication with theelectronics and for a method of powering and/or re-energizing theelectronics.

Often it is desirable to provide for communication to or from theembedded electronics for the purpose of control and/or data gathering.Communication of this nature should preferably be performed withoutdirect physical connection to the lens electronics, such that theelectronics may be fully sealed and to facilitate communication whilethe lens is in use. Hence it is desirable to couple signals to the lenselectronics wirelessly using electromagnetic waves. Accordingly, thereexists a need for an antenna structure appropriate for use in an opticallens assembly such as a contact lens.

The electronics in these applications often may require a power source.Accordingly, it may be desirable to incorporate a self-contained powerstorage device such as a rechargeable battery or capacitor. Alternately,the electronics may be inductively powered from a distance rather thanbeing powered from a self-contained power storage device, and thus thereis no need for recharging. An acceptable method for recharging a batteryis through inductive coupling, whereby an external coil is magneticallycoupled to a coil that is coupled to, connected to or otherwiseassociated with a charging circuit adapted to recharge the batteryimbedded in the device. Accordingly, there exists a need for inductivestructures, for example, antennas, antenna assemblies and/or coilsappropriate for use in an optical lens assembly. Further, it isdesirable to provide a convenient method for aligning the coil structurewith an external inductive coil structure for efficient near-fieldcoupling.

Embedding electronics and communication capability in a contact lenspresents general challenges in a number of areas, including the limitedsize of the components, in particular the thickness as well as themaximum length and width, the limited energy storage capacity inbatteries or super capacitators, the limited peak current consumptiondue to higher battery internal resistance in small batteries and limitedcharge storage in small capacitors, the limited average powerconsumption due to limited energy storage and the limited robustness andmanufacturability of small and especially thin components. With respectto communication devices, specific challenges include limited antennaefficiency, which is directly related to size or area and for a loopantenna, the number of turns, and antenna efficiency. In addition, thereis also a limited set of frequency bands allocated by regulatory bodiesfor these applications, the choice of which affects the efficiency of agiven structure, the maximum allowable transmitter power, potentialinterference, and other aspects of the communication link. Furthercharacteristics of on-body propagation and absorption depend onfrequency, along with accepted safe limits for absorption ofelectromagnetic energy. Various government agencies may or may not issueguidelines or regulations relating thereto. Antenna efficiency on-bodyis degraded for predominantly electric-field or “E-field” antennas.Similarly, for wireless charging of the battery or similar device, thesize of the antenna relates to the maximum inductance achievable and themaximum voltage or current that may be transferred to the device.

Accordingly, there exists a need for providing a mechanically robustantenna assembly that meets the requirements for functionality andperformance in the volume and area of a contact lens.

SUMMARY OF THE INVENTION

The antennas and/or antenna assemblies of the present invention overcomethe disadvantages as briefly set forth above.

In accordance with a first aspect, the present invention is directed toan ophthalmic lens assembly. The ophthalmic lens assembly comprising alens configured for placement in at least one of the inside andproximate to a surface of an eye, the lens including an optic zoneconfigurable for at least one of vision correction and visionenhancement, and one or more electronic components for enabling thevision correction and vision enhancement, and at least one antennaarrangement operatively associated with the one or more electroniccomponents for providing at least one of one or two way communicationwith the one or more electronic components and power transfer.

In accordance with another aspect, the present invention is directed toa lens assembly. The lens assembly comprising a lens, including an opticzone for at least one of image enhancement, image capture and visioncorrection, and one or more electronic components for enabling imageenhancement, image capture and vision correction, and at least oneantenna arrangement operatively associated with the one or moreelectronic components for providing at least one of one or two waycommunication with the one or more electronic components and powertransfer.

In accordance with yet another aspct, the present invention is directedto a lens assembly. The lens assembly comprising a lens, including anoptic zone for at least one of image enhancement, image capture andvision correction, and at least one antenna arrangement operativeassociated with the lens, wherein energization and de-energization ofthe at least one antenna arrangement causes a mechanical change in thelens.

In accordance with the present invention, an antenna or antenna assemblymay be incorporated into mechanical devices such as ophthalmic devices,including lenses and contact lenses. While exemplary embodiments will bedescribed with respect to contact lenses (wearable) or implantablelenses (IOLs), it is important to note that the present invention may beutilized in any number of related or non-related devices. Wearable orcontact lenses may incorporate a lens assembly having electronicallyadjustable focus to augment the performance of the eye and/or it mayincorporate electronic sensors to detect concentrations of particularchemicals in the tear film. The use of such embedded electronics in alens assembly potentially introduces the need for one and/or two waycommunication, and for a method of powering the electronics orrecharging a power storage device. The antenna/antenna assembly of thepresent invention may be utilized to transmit and/or receive informationand/or data as well as provide a means for charging the battery,batteries or capacitors utilized to power the electronics by inductivecharging or radio frequency (RF) energy harvesting methods. As known inthe relevant art, RF energy harvesting systems may be implemented wherecircuit operation is similar to inductive charging, but at higherfrequencies, for example, 900 megahertz to 2.4 gigahertz. In the art,“inductive charging” is often associated with low frequency, forexample, 125 kilohertz or 13.5 megahertz, near field coupling to acoil-like structure and RF energy harvesting is associated with longerdistance, lower power, higher frequency waves coupled to an RF antenna.

An exemplary optical lens assembly in accordance with the presentinvention may comprise a circuit board or substrate, an electroniccircuit, a lens structure (optics) and an antenna structure. Theelectronic circuit may comprise a number of electronic componentsmounted on the circuit board and the circuit board may provide wiringtraces to interconnect the electronic components. The circuit board maybe mechanically attached to the lens to form a rigid component of theoptical lens assembly. Alternately, the circuit board may not bemechanically attached to the lens and thus not form a rigid component ofthe optical lens assembly. This arrangement may vary depending on thetype of lens. In some exemplary embodiments, the antenna structure orantenna may include a coil comprising one or more loops of wire mountedaround and concentric with the lens structure. In alternate exemplaryembodiments, the antenna may comprise one or more wiring traces on thecircuit board. The antenna may be electronically coupled to theelectronic circuit. In some exemplary embodiments, the electroniccircuit may provide a transmittal signal to the antenna in order totransmit an outgoing electromagnetic signal board on the transmit signalwhile in alternate exemplary embodiments, the antenna may receiveincoming electromagnetic signal and provide a received signal to theelectronic circuit. In yet another alternate exemplary embodiment, theantenna may be utilized to transmit and receive signals. In yet anotheralternate exemplary embodiment, the antenna may be utilized toinductively charge a storage element or battery. In some exemplaryembodiments, a single antenna may also be utilized for bothcommunication and power transfer as is described in detail subsequently.

Antennas and antenna systems or assemblies incorporated into medicaldevices such as ophthalmic devices may be utilized or configured for awide variety of applications. Applications includetransmitting/receiving data to/from the ophthalmic device, sensinginformation from the environment in which the ophthalmic device isplaced, charging batteries associated with the ophthalmic device andactuation or activation of other devices. Data flow to and from theophthalmic device may include communication with key fobs, smart phonesor other hand-held devices and wireless networks, cases for holding theophthalmic devices, e.g. cleaning cases for contact lenses that utilizechemical or UV based disinfection systems, as well as any other types ofdevices capable of receiving text information, video information,telemetry information, graphics, software or code for reprogramming orupdating, and the like via an RF or inductive wireless link. The data orinformation to be transmitted or received may include tear filmanalysis, intra ocular pressure, heart rate, blood pressure and thelike. The ophthalmic device may be utilized to sense any number ofparameters depending on the device application, for example, ciliarymuscle contraction for an accommodating lens. Relatedly the output fromthe antenna or antenna system may be utilized to actuate or activatesecondary devices for changing the optics of the device and to dispensedrugs or therapeutic agents. The antennas and antenna assemblies may beutilized, as stated above, to recharge batteries or for continuouspowering from a remote source. This may be in the form of inductivepowering rather than charging. The antennas may also be utilized tocommunicate between ophthalmic devices, such as lenses, to detect eyeconvergence during reading or to synchronize behavior forthree-dimensional holographic realization.

The antennas and antenna assemblies may be physically realized in anynumber of ways. Physical realizations include conductive traces on acircuit incorporated in an ophthalmic device, and/or turns of wireembedded in the device, conductive traces printed in/on the device,and/or as a layer in a stacked die assembly. For example, an antenna maybe fabricated on a circular/washer or arc shaped layer, with traces onone or both sides of the layer, on substrate materials with theappropriate trace metallurgy. Multiple antennas on a single device maybe utilized as well.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other features and advantages of the invention will beapparent from the following, more particular description of preferredembodiments of the invention, as illustrated in the accompanyingdrawings.

FIG. 1A is a diagrammatic representation of a first exemplary embodimentof an optical lens assembly comprising a single loop antenna inaccordance with the present invention.

FIG. 1B is a diagrammatic representation of a first exemplary circuitboard of the optical lens assembly of FIG. 1A.

FIG. 2 is a diagrammatic representation of a second exemplary circuitboard in accordance with the present invention.

FIG. 3 is a diagrammatic representation of a third exemplary circuitboard in accordance with the present invention.

FIG. 4 is a diagrammatic representation of a second exemplary embodimentof an optical lens assembly comprising a coil antenna subassembly inaccordance with the present invention.

FIG. 5 is a block diagram representation of an antenna and receivercircuit in accordance with the present invention.

FIG. 6 is a block diagram representation of an antenna and transmittercircuit in accordance with the present invention.

FIG. 7 is a block diagram representation of an inductive chargingcircuit in accordance with the present invention.

FIG. 8 is a block diagram representation of a transmitter circuit incombination with an optical lens assembly comprising an antenna andreceiver in accordance with the present invention.

FIG. 9 is a block diagram representation of a primary inductive circuitin combination with a secondary inductive circuit incorporated into anoptical lens assembly in accordance with the present invention.

FIG. 10 is a block diagram representation of a contact lens inductivecharging system incorporated into a contact lens holding case inaccordance with the present invention.

FIG. 11 is a diagrammatic representation of a four turn spiral antennathat may be utilized for both communication and power transfer inaccordance with the present invention.

FIG. 12 is a diagrammatic representation of a die stack configuration inaccordance with the present invention.

FIG. 13 is a diagrammatic representation of the cross sections ofdesigns implementing antennas in contact lenses with the antennaconductors insulated from the conductive tear film in accordance withthe present invention.

FIG. 13A is a cross-sectional view of antenna traces on a substrate withinsulation in accordance with the present invention.

FIG. 14 is a simplified, diagrammatic representation of a contact lensand a single loop antenna in accordance with the present invention.

FIG. 15 is a diagrammatic representation of an antenna trace withparasitic coupling in accordance with the present invention.

FIGS. 16 A and B are schematic representations of an antenna on acircuit board in accordance with the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to FIG. 1A there is illustrated a first exemplary embodimentof an optical lens assembly 100. Although illustrated as a contact lens,it is important to note that the present invention may be utilized inconjunction with any number of devices having medical and ophthalmicapplications as well as any devices incorporating lenses, such ascameras, binoculars and microscopes. The exemplary optical lens assembly100 comprises a lens structure 102, a circuit board 104, an electroniccircuit 106 positioned on the circuit board 104, and a single turn loopantenna 108 also positioned on the circuit board 104 so as not tointerfere with the lens structure 102. As utilized herein, the lensstructure 102 may include a portion of an assembly that acts as anoptical lens and not necessarily a separate component, but rather aregion of a component such as a hydrogel overmolding. The electroniccircuit 106 and the antenna 108 may be connected to or mounted to thecircuit board 104 by any suitable means, for example, solder, wirebond,conductive epoxy, conductive ink and conductive polymer and in anysuitable configuration for any number of applications. The circuit board104 as used herein may include any suitable substrate, including coppertraces on a flexible polyimide substrate with a nickel-gold surfacefinish. Circuit boards are described in more detail subsequently. Theelectronic circuit 106 may comprise one or more electronic components110 mounted to the circuit board 104 and the circuit board 104 maycomprise interconnect conductive traces 112 to interconnect the one ormore electronic components 110. The circuit board 104 may be attached tothe lens structure 102 by any suitable means. For example, the circuitboard 104 may be mechanically connected to the lens structure 102 toform a rigid component of the optical lens assembly 100. The single-turnloop antenna 108 may be formed from any number of suitable conductivematerials and constructed utilizing any number of techniques. In theillustrated exemplary embodiment, the antenna 108 may be formed bywiring traces on the circuit board 104 and arranged to form anelectromagnetic structure having predetermined characteristics foroperation as an antenna, such as directivity, efficiency and/or gainwhen worn in a body or in-eye, or as an inductor for magnetic couplingto another inductor. The single-turn loop antenna 108 may beelectrically coupled to the electronic circuit 106 by wiring traces 112.As stated above, the antenna may be fabricated from any number ofsuitable conductive materials and alloys, including copper, silver,gold, nickel, indium tin oxide and platinum. Preferably, the antenna isfabricated from a non-reactive, biocompatible material.

FIG. 1B illustrates additional details of the circuit board 104 of theexemplary optical lens assembly 100 of FIG. 1A. The circuit board 104may comprise mounting pads 114 to facilitate electrical connection andmounting of the electronic components 110 (FIG. 1A). The mounting pads114 may be constructed from any number of suitable materials, forexample, the pads 114 may be constructed with the metal layer that formsthe metal traces 112 and may also be covered or more appropriately,plated utilizing any suitable process, with additional metal layers toimprove manufacturability and reliability as is known to one of ordinaryskill in the art. The circuit board 104 may also be constructed toprovide an opening 116 in which a lens structure or optics section 102may be mounted (FIG. 1A) or through which light may pass by a lensstructure mounted on one side of the circuit board 104. The circuitboard 104 may comprise conducting and insulating layers, for example,soldermask to cover the top conducting layer or insulators to separateconducting layers as is explained in greater detail subsequently. Thereare a wide variety of alternate configurations.

FIG. 2 illustrates an alternate exemplary circuit board 204 that may beutilized with the optical lens assembly 100 illustrated in FIG. 1A.Circuit board 204 comprises both top side conductive interconnect traces212 a and bottom side conductive interconnected traces 212 b (shown inphantom), through-holes or vias 218 for making electrical connectionsbetween the top and bottom sides, mounting pads 214, a center opening216 and a multi-turn loop antenna 220 rather than a single turn loopantenna. The multi-turn loop antenna 220 comprises two or more turns ofwire, conductive traces or the like formed in either or both of the topside or the bottom side of the circuit board 204. If multiple antennasare utilized on opposite sides, the through-hole or vias 208 may beutilized to make connections therebetween. It will be appreciated thatthe circuit board 204 may comprise additional metal layers and that anycombination of layers may be used to construct the multi-turn loopantenna 220.

Referring now to FIG. 3, there is illustrated yet another alternateexemplary circuit board 304 that may be utilized with the optical lensassembly 100 illustrated in FIG. 1A. The circuit board 304 comprises topside conductive interconnect traces 312 a, bottom side conductiveinterconnect traces 312 b, (illustrated in phantom) through-hole vias318, mounting pads 314, a center opening 316 and one or more spiralantenna structures 320. The one or more spiral antenna structures 320each comprise one or more turns of wire, conductive traces or the likeformed in either the top side metal, the bottom side metal or both thetop side and bottom side metal of the circuit board 304. If one or moreantenna structures 320 are utilized on opposite sides, the through-holevias 318 may be utilized to make connections therebetween. It will beappreciated that the circuit board 304 may comprise additional metallayers and that any combination of layers may be utilized to constructthe spiral antenna structures 320. The antenna structures alternatelymay be embedded on an inner conducting layer, with other conductinglayers above and/or below the antenna structures 320.

FIG. 4 illustrates another exemplary embodiment of an optical lensassembly 400. The optical lens assembly 400 comprises a lens structureor optics 402, a circuit board 404, an electronic circuit 406 and a coilantenna subassembly 408. The electronic circuit 406 may compriseelectronic components 410 mounted on the circuit board 404 and thecircuit board 404 may provide conductive interconnect traces 412 tointerconnect the electronic components 410. As in the previouslydescribed exemplary embodiments, the electronic components may beconnected to the circuit board 404 by any suitable manner, includingmounting pads (not illustrated). The circuit board 404 may be attachedto the lens structure 402 by any suitable means. For example, thecircuit board 404 may be mechanically connected to the lens structure402 to form a rigid component of the optical lens assembly 400. The coilantenna subassembly 408 may comprise one or more turns of wire or thelike on a circular form to create an electromagnetic structure havingdesirable characteristics for operation as an antenna, such asdirectivity, efficiency or gain when worn on a body or in eye, or as aninductor for magnetic coupling to another inductor coil. The coilantenna subassembly 408 may be electrically coupled to the electroniccircuit 406 by the wiring traces 412 and the electronic components 410.The notable or primary difference between the optical lens assembly ofFIG. 1A and the optical lens assembly of FIG. 4 lies in the antenna. Thedevice of FIG. 1A comprises a single-turn loop antenna 108 constructedwith the circuit board 104 whereas the device of FIG. 4 comprises a coilantenna subassembly 408 separate from the circuit board 404. This designmay provide benefits for fabrication, cost, assembly, antennaperformance, as well as other characteristics. The antenna subassembly408 may be integrated with the lens 402, for example, as a wire orprinted coils within the lens component.

It is important to note that the circuit boards described herein may beconstructed from any number of biocompatible materials or combination ofmaterials utilizing any number of fabrication techniques. A moredetailed description is given subsequently.

Referring to FIG. 11, there is illustrated an exemplary embodiment of asingle antenna 1100 that may be utilized for one or both communicationand power transfer. In FIG. 11, the single antenna 1100 is configured asa single four loop spiral antenna with a first tap point 1102 after thefirst loop and a second tap point 1104 after the fourth loop. The singleloop tap 1102 is intended, for example, for 900 megahertz while the fourloop tap 1104 is intended for 13.5 megahertz. A high pass filter 1106 iscoupled to the first tap point 1102 while a low pass filter 1108 iscoupled to the second tap point 1104. The high pass filter 1106 maycouple an electrical signal to an RF transmit or receive circuit such asfor communication or power coupling. The low pass filter 1108 may alsocouple an electrical signal to a lower frequency transmit or receivecircuit such as for communication or power coupling. Low and high passfilters may be implemented in a wide variety of configurations using awide variety of components and/or software as is known to one skilled inthe relevant art.

As is known in the relevant art, printed circuit boards are commonlymanufactured or fabricated with one or more layers of fiberglassreinforced epoxy laminate sheets such as FR-4 fiberglass epoxy or apolyimide flexible material to produce a flexible circuit board.Conductive circuit traces may be created by coating an insulating layerwith a predetermined thickness of copper or other suitable conductivematerial, applying a photoresistive material thereon, and selectivelypatterning and etching the material based on a desired circuit routingpattern. Multiplayer boards may be built up in layers with adhesive. Theupper traces may then be plated with nickel-gold or other materials toachieve suitable corrosion resistance, solderability and bondability.

Antenna traces may be created directly within the contact lens or anoptic insert. The lens molding process may allow for insertion of anantenna or deposition of an antenna within the polymer of the contactlens. An antenna may be deposited as a printed, curable trace duringmanufacture. An insert, containing the antenna, may be added to thecontact lens during molding. An antenna may be fabricated on an opticinsert by selectively depositing metal, broadly depositing thenselectively removing metal, depositing a liquid curable conductor, orother means. The functionality of the antenna is similar to what hasbeen described for a circuit board; however, the physical realization ison a polymer or plastic instead of typical circuit board materials.

A coil subassembly may be manufactured by winding enamel coated wire ona cylindrical form that is incorporated as part of a lens assembly.Alternately, wire may be wound onto an outer part of the lens structureitself and optionally bonded (glued) or otherwise attached to the lensstructure. Any suitable means for attaching the wire to the lens, forexample, small tabs may be utilized to secure the windings in position.In yet another alternate embodiment, a coil may be created byselectively etching, for example with a laser or mechanical means, aspiral or circular pattern of conductive traces in a conductive layer onan outer or inner portion of the lens assembly.

An antenna may also be realized in a contact lens by first fabricating astacked die structure which is then embedded within the contact lens. Anantenna may be fabricated on a circular/washer or arc-shaped layer, withconductive traces on one or both sides of the layer, on substratematerials like glass, silicon or alumina, with the appropriate tracemetallurgy. An antenna layer may be combined with other layers to forman electronic system, potentially including batteries, sensors and anynumber of other electronic circuits or devices. The antennas may beconfigured as full loops or partial loops on opposite sides of a deviceor bypassing other devices, and all be interconnected through viasand/or bridges.

FIG. 12 illustrates an exemplary stacked die arrangement incorporatedinto a contact lens 1200. As illustrated, the contact lens comprises anoptic lens zone 1202, one or more layers of electronic components 1204,and at least one antenna layer 1206. The optic lens zone 1202 comprisesa front optic, a rear optic and a metalized flange 1208 on the perimeterthereof. The stacked die is encapsulated into the polymer forming thelens 1200. It is important to note that any of the antennas describedherein, including the single-turn loop antenna, the multi-loop antenna,the spiral antenna or the coil antenna subassembly may also beencapsulated into the polymer forming the lens with or without asubstrate.

Regardless of the physical implementation of the conductive antennatraces, for example, a wire coil configuration, on a circuit board, viaa stacked die or conductive traces printed directly on and/or in thematerial forming the lens, the antenna traces should preferably beinsulated from the surrounding conductive fluids found in or on the eye.The eye's tear film is composed of three layers. The first or bottomlayer is the layer that coats the eye and comprises mucin which iscreated by cells in the conjunctiva referred to as goblet cells. Themucin fills in microscopic irregularities on or in the eye's surfacewhich is important to clear vision. The second layer or middle layer ofthe tear film comprises a watery substance that makes up the bulk of thetear film. A majority of the watery component is produced or suppliedfrom the main lacrimal or tear gland. The third or top layer of the tearfilm comprises a thin layer of oil secreted by the meibomian glands andfunctions to prevent the tears from evaporating too quickly. The aqueoushumor is a clear waterlike fluid within the anterior chamber between thecornea and the crystalline lens of the eye which is similar to bloodplasma in composition. The vitreous humor is a jellylike fluid in theposterior chamber between the crystalline lens and the retina of theeye. Both tears and aqueous humor may contain conductive components.Accordingly, without proper insulation, undesirable shorts could developbetween antenna traces, or the performance of the antenna may bedegraded by the presence of a nearby conductive fluid or material with ahigh dielectric constant. For example, a tear film, as stated abovecomprises a conductive solution of water and salt ions. Human tissue aswell as tear film also exhibit dielectric properties which could changethe tuning, frequency response and efficiency of the antenna.

Referring now to FIG. 13, there is illustrated, in cross-section, threeexemplary embodiments of antenna configurations in lenses, for example,contact lenses. Lens 1300, as illustrated, comprises a flexible circuitboard 1302 on which the antenna traces 1304 may be patterned. Alsomounted to the circuit board 1302 is the lens module 1306 and electroniccomponents 1308. An insulating layer 1310 is coated on the antennatraces. The contact lens polymer 1312 encapsulates the entire assembly.Lens 1320, as illustrated, comprises a stacked die arrangement 1322 withan antenna layer 1326 as the top layer. The stacked die arrangement 1322also comprises a number of layers of electronic components 1328, 1330and 1332 arranged in layers. Layer 1328 may comprise a number offunctional components, for example, an integrated circuit RF receiver.Layer 1330 may comprise, for example, multiple battery layers or otherenergy storage devices. Layer 1332 may comprise additional circuitry orantennas. An insulating layer 1324 may be coated on top of the antennalayer 1326. Once again, contact lens polymer encapsulates the entireassembly. Lens 1340 as illustrated, comprises an antenna 1342 mounteddirectly on the polymer forming the lens 1344 with an insulating layer1348 positioned thereon. An integrated circuit 1346 may be connected tothe antenna 1342, for example, as an RF receiver. The contact lenspolymer encapsulates the whole assembly.

The insulating layers 1310, 1324 and 1348 may be implanted in any numberof ways. For example, on a circuit board, it is typical to implement asoldermask layer which insulates all traces except for defined padswhich are left open to permit connection to components such as discretecomponents, battery and/or integrated circuits. In a die stackarrangement, underfill or other adhesives or encapsulants may be used asis standard practice in die attachment and packing. For a designutilizing antenna traces realized directly on the optic polymer, aninsulating layer may be deposited through standard deposition or coatingtechniques known in the semi-conductor processing industry. Any of theseapproaches may undergo further insulating or encapsulation, includingparalyne coating, dielectric deposition, dip coating, spin coating orpainting. The insulating material must have sufficient dielectricstrength in the presence of an applied electromagnetic field given thespecific trace geometry and separation.

Referring now to FIG. 13A, there is illustrated, in cross-section, acontact lens 1360 having multiple components, including antenna traceson a substrate with insulation thereon. The substrate 1362 may compriseany suitable surface, including a circuit board, silicon or othermaterial used in a die stack, optic plastic/polymer, or any othersubstrate material suitable for use with optic and metallic traces. Theantenna traces 1364 may be formed on the substrate 1362 utilizing anysuitable technique such as those described herein. For an antennaimplemented as a wire assembly, the antenna may not be formed directlyon the substrate. An insulating layer 1366 provides electrical andmechanical insulation between the antenna traces 1364 and also betweenthe antenna traces 1364 and the surrounding environment, which mayinclude a biocompatible polymer 1368 and the ocular environment 1370which includes the tear film and the like which comes into contact withthe lens 1360. The insulating layer 1366 and the biocompatible polymerlayer 1368 may also provide chemical as well as mechanical insulationfor the antenna traces 1364 and the substrate 1362.

The physical separation between the antenna and nearby substances withhigh permittivity or nearby objects connected to various circuit nodescan affect the antenna frequency response, tuning, and efficiency.Parasitic capacitance may be distributed around the loop antenna causingsubstantially altered performance from the design goal. Other circuittraces should be kept as far as possible from the antenna trace to avoidparasitic coupling. Electromagnetic field simulations should beperformed to design the antenna in the presence of nearby objects andsubstances.

Turning now to FIG. 15, there is illustrated a diagrammaticrepresentation of antenna trace parasitic coupling. The antenna trace1502 may be implemented on any suitable substrate 1500, which mayinclude a circuit board or a die stack utilizing any suitable techniquessuch as those described herein. Other components 1506 mounted on thesubstrate 1500 and located proximate the antenna trace 1302 may coupleto the antenna trace 1502 through parasitic capacitance represented bycapacitor 1504. As previously described, as well as known in the art,this coupling may significantly impact antenna performance. However,this parasitic coupling may be reduced by increasing the separation 1508between the antenna trace 1502 at the other components 1506 by distanceor through shielding material.

FIGS. 16A and 16B are schematic representations illustrating the conceptset forth with respect to FIG. 15. In FIG. 16A, antenna trace 1602 oncircuit board 1614 is close to traces 1604, 1606, 1608 and 1610 as wellas electronic component 1612. Each of these conductive traces and/orelectronic components may cause distributed parasitic capacitance alongthe antenna trace 1602. Accordingly, a single solution is illustrated inFIG. 16B, wherein the antenna trace 1602′ on circuit board 1614′ isseparated from traces 1604′, 1606′, 1608′ and 1610′ as well as component1614′, thereby decreasing parasitic capacitance and improving antennaperformance.

Antennas or antenna systems may serve as a means for receiving signals,as a means for transmitting signals, as an inductive coupling means, orany combination thereof. The function of an antenna determines itsdesign as well as its supporting circuitry. For example, an antenna maybe coupled to a receiver circuit, a transmitter circuit, an inductivecoupling circuit or to any combination thereof. Basically, an antenna isan electrical device that converts electromagnetic waveforms intoelectrical signals, electrical signals into electromagnetic waveforms,or electrical signals into different electrical signals. The discussionbelow focuses on the three different uses of an antenna and itsassociated circuitry.

It is important to note that the circuits set forth and describedsubsequently may be implemented in a number of ways. In one exemplaryembodiment, the circuits may be implemented using discrete analogcomponents. In another exemplary embodiment, the circuits may beimplemented in integrated circuits or a combination of integratedcircuits and discrete components. In yet another alternate exemplaryembodiment, the circuits or particular functions may be implemented viasoftware running on a microprocessor or microcontroller.

Referring to FIG. 5, there is illustrated an antenna 502 and associatedradio receiver 500. The radio receiver electronic circuit 500 comprisesan antenna match circuit 504, a receiver circuit 506, a controller 508,an actuator 510, a battery 512 and a power management circuit 514. Inthis configuration, the antenna 502 is adapted to receive anelectromagnetic signal 501 and to provide a received electrical signalto the antenna match circuit 504. The antenna match circuit 504 maycomprise any suitable circuitry necessary for balancing the impedancebetween the source and the load to maximize power transfer and/orminimize reflection from the load. Essentially, antenna impedance is theratio of voltage to current at any point on the antenna and forefficient operation, the antenna impendence should be matched to theload, and thus a match circuit is utilized. In this instance, the matchcircuit 504 is adopted to provide an impedance match between the antenna502 and the receiver circuit 506 for an optimum power match, noise matchor other match condition as is known in the radio and circuit designarts. The receiver circuit 506 comprises any suitable circuitrynecessary to process the modulated signal received by the antenna 502and provide a demodulated signal to the controller 508. For purposes ofclarity, modulation involves varying one or more properties of a signalor electromagnetic waveform. For example, a waveform may be amplitudemodulated (AM), frequency modulated (FM) or phase modulated (PM). Otherforms of analog as well as digital modulation exist. Demodulation, onthe other hand, involves extracting the original information bearingsignal from the modulated carrier wave. It is this demodulatedinformation signal that provides instructions to the controller 508. Thecontroller 508 in turn provides a control signal to the actuator 510based upon the demodulated signal in order to control a state oroperation of the actuator 510. The control signal may be further basedon any internal state of the controller (for example, to implementcontrol laws) and/or any other circuits coupled to the controller (forexample, to implement a feedback control system or to modify theactuator operation based on other information, such as information basedupon sensor data). The battery 512 provides a source of electricalenergy for all components in the electronic circuit 500 requiring energye.g. active components. The power management circuit 514 is adapted toreceive a current from the battery 512 and condition it or regulate itto provide a workable output voltage suitable for use by the otheractive circuits in the electronic circuit 500. The controller 508 mayalso be utilized to control the receiver circuit 506 or other circuitsin the receiver 500. The antenna 502 may comprise one or more of theconfigurations described herein. For example, a single-turn loopantenna, a multi-turn loop antenna, a spiral antenna, a coil antennasubassembly or a stacked-die configuration or arrangement.

As is known in the relevant art, the optimum transfer of power betweenan antenna and a receiving and/or transmitting circuit requires matchingthe impedance presented to the antenna and the impedance presented tothe circuit. Essentially, optimum power transfer occurs when thereactive components of the antenna and circuit impedances are cancelledand the resistive components of the impedances are equal. A matchingcircuit may be introduced to couple the antenna to the circuit thatmeets the optimum power transfer criterion at each, thereby allowing foroptimum power transfer to occur between the antenna and circuit.Alternately, a different criterion may be selected to optimize adifferent parameter such as maximum current or voltage at the circuit.Matching circuits are well known in the art and may be implemented withdiscrete circuit component such as capacitors, inductors and resistors,or with conductive structures, such as traces in a circuit board, thatprovide a desired impendence characteristic.

Impedances of small RF loop antennas are typically between 20 and 50nanohenries, and matching component valves are in the range of 0.5 to 10picofarads for capacitors and 3 to 50 nanohenries for inductors.Impedances of inductive charging coils are typically between 100nanohenries and 5 nanohenries and associated capacitors for resonatingthe circuits are between 20 and 100 picoforads.

The actuator 510 may comprise any number of suitable devices. Forexample, the actuator 510 may comprise any type of electromechanicaldevice, for example, a pump or transducer. The actuator may alsocomprise an electrical device, a chemical release device or anycombination thereof. The actuator 510 may be replaced with a controlleddevice such as a light emitting diode or diode array or any othersuitable display or user interface. In other words, the circuit 500 mayutilize an actuator (action device) or a controlled device (passivedevice). As used in this context, a passive device is a device that doesnot output to or control another device, for example, actuators such asmotors are active whereas displays or monitors are passive. In contrast,in electronics terminology, there are passive electronic devices such asresistors, capacitors and inductors and active devices such astransistors. Active devices as used in this context are devices capableof changing their “operational performance,” such as transistors.

The battery 512 may comprise any suitable device for the storage ofelectrical energy. For example, the battery 512 may comprise anon-rechargeable electrochemical cell, a re-chargeable electrochemicalcell, a storage electrochemical cell, and/or a capacitor. In alternateexemplary embodiments, no battery may be required as explained abovewith respect to RF energy harvesting or near field inductive coupling.Alternatively, mechanical vibration and similar means may be utilized togenerate or harvest power.

The power management circuit 514 may comprise additional circuitry for awide variety of functions in addition to regulating the output of thebattery 512. For example, the power management circuit 514 may comprisecircuitry for monitoring various battery parameters, such as charge,preventing overdischarge of the battery, and supervising the start upand shut down of the electronic circuit 500.

Referring now to FIG. 6, there is illustrated an antenna 602 andassociated radio transmitter or radio transmitter circuit 600. The radiotransmitter electronic circuit 600 comprises an antenna match circuit604, a transmitter circuit 606, a controller 608, a battery 610, a powermanagement circuit 612 and a sensor 614. In this exemplary embodiment,the antenna 602 is adapted to receive a matched transmit electricalsignal from the match circuit 604 and broadcast or radiate a transmitelectromagnetic signal 601 based on the transmit electrical signal.Similarly to that described above, the match circuit 604 may beconfigured to provide an impedance match between the antenna 602 and thetransmitter circuit 606 for an optimum power match, noise match or othermatch condition as is known to one of ordinary skill in the signalprocessing art. Rather than working in conjunction with an actuator, thecontroller 608 is coupled to and configured to receive a sensor datasignal from the sensor 614. The sensor 614 may comprise any type ofsensor, including mechanical sensors, chemical sensors, and/orelectrical sensors. The controller 608 provides a transmit data signalto the transmitter circuit 606 based on the sensor data signal from thesensor 614. The transmit data signal may be further based on an internalstate of the controller 608 and/or the state of the other circuitscoupled to the controller 608. As before, the battery 610 provides asource of electrical potential energy for any of the componentsrequiring energy (active components). Once again, the power managementcircuit 612 is configured to receive current from the battery 610 and toprovide a regulated supply voltage to the other active components in thecircuit 600. The antenna 602 may comprise one or more of theconfigurations described herein. For example, a single-turn loopantenna, a multi-turn loop antenna, a spiral antenna. a coil antennasubassembly or a stacked-die arrangement or configuration.

FIG. 7 illustrates an electronic circuit 700 comprising an inductivecharging receiver. The electronic circuit 700 comprises a rectifiercircuit 702, a battery charging circuit 704, a battery 706, a powermanagement circuit 708, a controller 710 and an actuator 712. Asecondary inductive circuit 714 is coupled to and provides a powersignal to the rectifier circuit 702. The secondary inductive circuit 714is essentially an inductive circuit in which the current is produced bya magnetic field from a primary circuit (not shown). In the simplestterms, a rectifier circuit converts an alternating current to a directcurrent. The rectifier circuit 702 is illustrated in its simplest form,essentially using a diode to allow current to flow in a singledirection. The inductive circuit 714 is also shown in its simplest formwith a coil in which current is utilized to create a magnetic field.Both of these circuits may be much more complex depending on what isneeded for the particular application. Those skilled in the art willrecognize many alternate exemplary embodiments of resonant circuits andrectifier circuits, including full wave bridge rectifiers which may ormay not be coupled to inductors having a secondary tap that may improvethe efficiency of the rectification, but essentially perform the same orsimilar function. The rectifier circuit 702 rectifies the power signalto provide a direct current (DC) signal to the battery charging circuit704. The battery charging circuit 704 is coupled to the battery 706which is also coupled to and provides energy to the power managementcircuit 708. It is important to note that while the figure illustratesan explicit connection at a single node coupling the battery chargingcircuit, the battery and the power management circuit, there are a widevariety of implementations with separate “managed power paths” withswitches and switching networks to selectively couple the one or moredevices. The power management circuit 708 may provide a regulatedvoltage supply to the controller 710 and actuator 712. The controller710 may be further configured to receive an indicator signal from thepower management circuit 708 and to provide control signals to the powermanagement circuit 708. The controller 710 provides an actuator controlsignal to the actuator 712. In operation, the battery charging circuit704 may sense the battery voltage of the battery 706 and the availablevoltage from the rectifier circuit 702. If the available voltage isgreater than the battery voltage and if the battery voltage is below adesired charged level, then the battery charging circuit 704 may chargethe battery until either the available voltage is too low or the batteryvoltage reaches the desired charged level. The controller 710 mayoperate under the control of an internal state machine or microprocessorcore and software to periodically enter a low or high power state, andto command the power management circuit 708 to change an operating modeand to control the actuator 710. The power management circuit 708 maysense the battery voltage and provide an indication of the state ofcharge of the battery 706 on the indicator signal. The operation of thecontroller 710 may depend on the indicator signal and therefore thestate of charge of the battery 706. The secondary inductive circuit 714may comprise one or more of a single-turn loop antenna, a multi-turnloop antenna, spiral antenna structures, or a coil antenna subassembly.

Referring now to FIG. 8, there is illustrated an exemplary transmitterand an exemplary optical lens assembly comprising a receiver asillustrated in FIG. 5. As illustrated, the overall system 800 comprisesa control transmitter 802 and an optical lens assembly 804. The controltransmitter 802 may comprise an antenna 806, a transmitter circuit 808,a battery 810 and a user interface 812. For example, the user interface812 may be an optional component. The antenna 806 may comprise anysuitable device such as those disclosed herein. It is important to notethat the battery 810 may comprise any suitable device, includingrechargeable batteries, non-rechargeable batteries, one or morecapacitors and a power supply that works with an AC adapter as describedabove. The user interface 812 is coupled to the transmitter circuit 808and may provide buttons or similar means for a user to control and/orobserve the status of the transmitter circuit 808. In other words, theuser interface 812 may comprise any suitable means through which a useror operator may command and communicate with the transmitter circuit 808such as buttons, touch screen displays or any other known means. Thetransmitter circuit 808 generates and provides and electrical transmitsignal to the antenna 801 in order to broadcast a transmitelectromagnetic signal 801. The transmit electromagnetic signal 801 maybe based on control information provided by the user/operator and/or maybe based on an internal state of the transmitter 802. The optical lensassembly 804 may also comprise an antenna 814, an electronic circuit816, which may be substantially similar to the circuit 500 of FIG. 5,and a lens structure 818 with which the antenna 814 and the electroniccircuit 816 are incorporated.

Whereas FIG. 8 illustrates an exemplary transmitter and an exemplaryoptical lens assembly, FIG. 9 illustrates an exemplary inductivecharging system 902 and an exemplary optical lens assembly 904,including a secondary inductive circuit 906 and an electronic circuit914. The inductive charging system 902 comprises a primary inductivecircuit 908, an inductive transmitter circuit 910 and a battery 912. Thebattery 912 provides a source of electrical potential energy to theinductive transmitter circuit 910. The inductive transmitter circuit 910generates and provides a drive signal to the primary inductive circuit908 in order to generate an alternating magnetic field in the primarycircuit 908. The primary inductive circuit 908 may comprise any suitabledesign, for example, with either series or parallel circuit arrangementsas is well known in the relevant art. The optical lens assembly 904comprises a secondary circuit 906 and an electronic circuit 914. Duringthe charging operation, the secondary circuit 906 may be magneticallycoupled to the primary circuit 908 such that the induced magnetic fieldinduces a current in the secondary circuit 906 which is provided to theelectronic circuit 914. The electronic circuit 914 may comprise acircuit substantially similar to circuit 700 (FIG. 7) and the secondarycircuit 906 may comprise any type of antenna such as those discussedherein. The electronic circuit 914 and the secondary circuit 901 may beincorporated into an optical lens assembly 916 in any suitable mannersuch as any of the exemplary embodiments described herein.

The charging system illustrated in FIG. 9 may be incorporated into anynumber of suitable devices. FIG. 10 illustrates an exemplary contactlens case 1002 incorporating a charging system. The exemplary contactlens case 1002 comprises lens holder 1004, a circuit board 1006, aninductive transmitter circuit 1008, a power-source 1010, and a primaryinductive antenna structure 1012. A contract lens 1014 comprises acircuit board 1016 and a secondary inductive antenna structure 1018. Thelens 1014 is illustrated in profile and thus the optical structure isnot shown. In operation, a user simply places the lens 1014 into thelens holder 1004. The lens holder 1004 is shaped in a manner tooptimally align and achieve a desired amount of magnetic couplingbetween the secondary inductive antenna structure 1018 with the primaryinductive antenna structure 1012 an indicated by magnetic field lines1001.

Typically, for wireless communication, there is a range of frequencies,around 900 megahertz and 2.4 gigahertz where power levels allowed byregulating bodies are sufficient for communication and RF energyharvesting. Such frequency bands, are known as the 866 megahertzEuropean ISM band, the 915 megahertz ISM band and the 2.4 gigahertz ISMband. For power transfer, a frequency of about 13.56 megahertz asspecified in a common RFID band, provides a relatively high allowablefield strength and high enough frequency to have efficient coupling tosmall structures. Regardless of the normal frequencies and powerutilized for a particular application, when using a device on, in ornear a biological organism, the various parameters may need to betailored for safety.

Energy harvesting is a process hereby energy is derived from any numberof external sources, captured and then stored for use. A typical exampleis an RFID system, wherein a radio transmitter broadcasts RF energy topower remote devices. The FCC and/or other similar regulatory agenciesset forth specific guidelines for transmission, including power levels,which address various issues including safe levels of energy.

In an alternate exemplary embodiment, lenses may be constructed whereinthe lens itself responds to the energization and de-energization of anantenna rather than use additional electronics. For example, an antenna1400, as illustrated in FIG. 14, may be mounted in a lens 1402 in amanner such that when it is energized it may cause the lens 1402 toassume one specific shape and/or configuration and another or restingshape and/or configuration when it is de-energized. Its operation may besimilar to the use of a piezoelectric material. The antennas 1400 maydirectly connect to an electro-optic lens such that the current inducedin the antenna when energized by an external electromagnetic fieldcoupled to the lens 1402 causes it to activate. Essentially, all that isrequired to implement such a system would be a convenient transmit powersource and a receive antenna which may be implemented within theconstraints of a contact lens. Preferably, only the antenna would berequired with no additional tuning components.

It is important to note that any number of antenna designs andassociated circuitry may be utilized in accordance with the presentinvention. The antenna of the present invention may be utilized for anumber of applications, including actuation of other elements, includingvision correction, dispensing therapeutic agents and photochromaticdiming, charging onboard batteries and similar energy storage devices,continuous powering from a remote source and energy harvesting,transmitting data to and/or from the lens, and sensing on the eyeitself. The transmission of data to and/or from the lens may include anytype of information, including biometric data.

As described herein, the antennas may take on any number of forms,including traces on a circuit board, turns of wire embedded in the lens,printed on the lens and as a layer in a stacked die arrangement.Associated with the antennas are antenna related circuits. Radiofrequency matching may be realized with discrete components, integratedcircuits, integrated passive devices, MEMS tuners and switches.Resonating and load structures include parallel resistance to define theload and Q factor, series and/or parallel resonance, and tunablestructures to adapt to the environment.

Any antenna designed preferably is designed to work on-body and beembedded in a saline environment with limited area and volume available.Accordingly, small magnetic loop devices are preferred, as monopoles anddipoles as well as similar antennas are not good on-body or in saline.

Any of the antennas set forth herein, e.g. coils, as well as any otherantenna design may be realized using a fractal design, as is known inthe relevant art, to optimize performance, including size, efficiency,input impedance, bandwidth and multiband usage. Essentially, a fractalantenna is any antenna structure that uses a fractal, self-similardesign to maximize the length or increase the perimeter of a materialthat is able to transmit and/or receive electromagnetic radiation withina given total surface area or volume. Antenna tuning units are generallynot required for use with fractal antennas due to their wide bandwidthand complex resonance.

As set forth herein and as it known in the art, antennas function bytransmitting and/or receiving electromagnetic waves. There are a numberof key factors which must be addressed in any antenna design and theyinclude, gain, efficiency, impedance, bandwidth, polarization,directionality and radiation pattern. These factors are all importantand can be varied depending on the application. For example, if anantenna is to be utilized in a contact lens, the antenna is preferablydesigned as a directional antenna with the bulk of radiated powertravelling out of the eye and away from the head. Desired frequency andbandwidth may be selected or chosen depending on availability anddesired functionality. Impedance, i.e. the voltage to current ratio atthe input of the antenna may also be determined by the specific design.

Although shown and described is what is believed to be the mostpractical and preferred embodiments, it is apparent that departures fromspecific designs and methods described and shown will suggest themselvesto those skilled in the art and may be used without departing from thespirit and scope of the invention. The present invention is notrestricted to the particular constructions described and illustrated,but should be constructed to cohere with all modifications that may fallwithin the scope of the appended claims.

What is claimed is:
 1. An ophthalmic lens assembly comprising: a lensconfigured for placement in at least one of the inside of an eye or onthe surface of an eye, the lens including an optic zone configurable forat least one of vision correction and vision enhancement and aperipheral zone; a stacked die structure comprising one or moresubstrate layers each having an upper and lower surface, the one or moresubstrate layers having an annular configuration; one or more mountingstructures attached to at least one of the upper and lower surfaces ofthe one or more substrate layers; one or more electronic componentsattached to the one or more mounting structures, the electroniccomponents configured to control the functionality of the lens; and atleast one antenna arrangement operatively associated with the one ormore electronic components and configured for at least one of thetransmission of signals between the one or more electronic componentsand an external device, the reception of signals between the one or moreelectronic components on an external device, and inductive coupling, theat least one antenna arrangement being affixed to at least one of theupper and lower surfaces of the one or more substrate layers andisolated to reduce parasitic capacitance, wherein the stacked diestructure, the one or more mounting structures, the one or moreelectronic components and the at least one antenna are encapsulated inthe peripheral zone of the lens, the stacked die structure beingconfigured to arrange the one or more substrate layers such that allcomponents fit within the peripheral zone.
 2. The ophthalmic lensassembly according to claim 1, wherein the lens comprises a contactlens.
 3. The ophthalmic lens assembly according to claim 1, wherein thelens comprises an intraocular lens.
 4. The ophthalmic lens assemblyaccording to claim 1, wherein the lens comprises a spectacle lens. 5.The ophthalmic lens assembly according to claim 1, wherein the at leastone antenna arrangement comprises one or more single-turn loop antennas.